Improvement ijn signal-boxes for fire-alarm telegraphs



M. a. CRANE.

Signal vBox4 for Fir-e Alarm Telegraphs. N0 155,918, y Patentedjulyznw.

Imm@ h UNITED STATES.

PATENT OFFICE.

"MosEs e. cEAEE, or NEwTort, MASsAo,HUSETTS Specification formingpart of Letters Patent N0.. 165,9,.lShdated July 27, 1875; application filed Jury 9, 1875.

17o-all. whom it may concern.;

Be it known that. I, MOSES G. CRANE, of Newton, county of Middlesex, in the State of Massachusetts, have invented an Improvement in Automatic Signal-Boxes for Electro,- Magnetic Fire-Alarm. Telegraphs,.of which the 4following isa specification,` reference being had to the accompanying drawings forming part of this spectation.

Figure l is a front elevation of a signal-box embodying my invention.` Fig. 24 is central sectional view of the cover of the said box, showing the lever employed tese@ thevmechanism ofthe signalfbox in 4motionto give a fire- Fi gs. 3 and 4 are detailed views of the.

second claim therein is stated to consist ofV the combination, with the armature of the magnet and the winding lever or crank of the signal-box, of a device whereby the armature is, by the movement of the lever, locked in the position it occupies when attracted to the magnet, if', at the moment when the lever is moved, the circuit is closed, and whereby it is locked away from the magnet, if, at the moment when the lever is moved, the circuit is broken, the wires of the circuit being so arranged that when the armature is attracted to the magnet the electric current passes necessarily over the break-circuit wheel, but when the armature is released from the magnet the electric current is transmitted by a shorter route, cutting the l break-circuit wheel out of the circuit.77 The object ot' the invention is, as there stated, to secure the orderly giving of' signals by preventing the interfering of any signal-box with any other circuit.77

My invention consists in the. improved dcvices and combinations hereinafter described, differing from those described in the said patent for accomplishing substantially the same object.

The general construction and operation` of .the mechanism constituting the signal-box do only my new devices and combinations, with a general reference` tothe remainder of the mechanism.

A is the breakcircuit wheel, rotated by the lstress of the mainspring C through the train of wheels shown in Fig. 1. D is the electromagnet, the armature a of which is fixed upon the lever b, that is pivoted at its upper end `in a bracket, c. Secured upon this lever is a plate, d, of rubber or other insulator, upon which is secured a metal piece, e. f denotes a metal finger fixed and insulated at one end upon the support E, with which is connected the circuitwire g. The other end extends downward, and touches the plate e when the armature is swung away from its magnet, as`

Seen in the drawing. There are two of` these lingers, and with the other is connected, the

leaves it through the binding-screw i. One

wire, fm, within the box runs from the bindingscrew to the magnet D in connection with metal linger u, that rests on the break-circuit wheel A, thus bringing the said wheel into the circuit. Another wire, o, avoiding the breakcircuit-wheels, runs to the fingers f, over which the circuit is completed, when the metal plate e touches said lingers.

F, one of the gear-wheels of the train, has on its side face, at its periphery, a flange, p, seen more plainly in Figs. 3 and 4. G is a lever, pivoted at one end at s. Upon the opposite end is a hook or upward wedge-like projection, t. This lever rests upon the flange p, toward which it is pressed by a spring, u. Upon its under side is a lug, V, and in the llange p a notch, V', into which the lug falls when the wheel F is in position, where the lug. and notch coincide. While the lug is in the said notch the wheel F is locked and cannot revolve. But by lifting the lever G, the

lug being thereby disengaged from the notch, the wheel F will make, under the stress of the mainspring, a complete revolution, the lug resting meantime on the ange, and thereby maintain the lever in its raised position.. The

wheels of the train may be so proportioned .that the break-circuit wheel will make any Y, lever G isrraised, the circuit is open, and theY lever b, by stress of the spring z', is thrown to Ithe left, the hook t will be thrown up on the right side ofthe end of` said lever and lock it in that position, with the circuit closed over the fingers f.

H is a lever pivoted in the cover I of the box, one arm, X, of which extends into the box, immediately under the hooked end of the lever G. The opposite end X" of the lever H extends outward from the box-cover. The person giving an alarm depresses this end X' of the said lever, and thereby throws up the lever G. As soon as the pressure isremoved from X thespring Y throws down the end X and leaves the lever G free to fall back to its first position when the wheel F shall have made a revolution.

This box is intended to be used with a closed circuit, and the alarm to be given by breaking the circuit; and it is evident that the circuit being closed, and any one of a number of signal-boxes in such circuit being pulled or set in motion to give a signal, the upward movement of the lever G will lock the lever b in position to prevent connection between the fingers f and the plate e, thus locking the break-circuit wheel of such signaling-box in circuit until the signal is completed, but that in all other boxes in the circuit the corresponding armature levers will be swung away from the magnets and close the circuits over the corresponding fingers f, thus locking the break-circuit wheels of all of' them out of circuit, so that if, while a signal is being given by one box, any other box in the circuit should be pulled,77 no eect will be thereby produced and no interference with the signalning-box occasioned. Y Y o Y. Y. t I do not claim as my invention the general mechanism ofthe box described, whereby noninterference between boxes in the same circuit is effected, limiting my claim to the following special devices, viz: The lever G with its lug V and hook t, the Bange 1o on the wheel F, and the lever b, combined as described.

What I do claim, and desire to secure by Letters Patent, is

l. In a re-alarm signal-box the lever G,

with its lug V and hook t, the flange lo and its' notches V', the lever b, insulated plate e, and magnet D, all combined and operating as and for the purpose specified.

2. The combination of the lever H, the lever G, and the wheel F, whereby the said wheel is liberated and allowed to revolve under the stress of the motor G, as and for the pur- MOSES G. CRANE.

Witnesses:

A.' S. FITCH, B. S. CLARK. 

